(a) Technical Field of the Invention
The present invention relates to a pivotal mechanism for suspending a lens to a spectacle, and in particular, a mechanism which pivots a lens onto the spectacle and facilitates removal of the lens when not in use.
(b) Description of the Prior Art
Taiwanese Utility Model Patent No. 145922 entitled “Combination Structure of a spectacle and frame thereof” discloses a lens mounting spectacle frame having elongated magnets on the two sides of the frame above spectacle support on the nose, and the top of the nose support is provided with a positioning hole corresponding to the lower center of the nose support having a positioning peg. These two components can be mounted to each other, providing positioning and avoiding sliding of the lens that suspends thereto. Even though there are magnets to attract the mounting of the lens and the positioning peg can secure the mounting by inserting the peg into the positioning hole, the area of the magnet is small and the attraction force is limited and mounting by magnet is only limited to attraction force in vertical direction. The positioning peg is easily dislocated from the positioning hole in the course of jogging, jumping or riding in a vehicle on a bumpy road. Further, after long period of use, the magnet may react with oxygen in the air, as a result, oxidization, demagnetization, decolorization, etc may occur. The connection between the frame and the lens may also be contaminated with drifts.